code: def test_trivial(self, Source):
      source = Source()
  
      e_img, e_crs, e_extent = source.single_tile(-3, 50)
      r_img, r_crs, r_extent = source.combined(-3, 50, 1, 1)
      assert_array_equal(e_img, r_img)
      assert e_crs == r_crs
      assert e_extent == r_extent
  
file_path: cartopy/lib/cartopy/tests/io/test_srtm.py
imports: import numpy
  from numpy.testing import assert_array_equal
  import pytest
  import cartopy.crs
  import cartopy.io.srtm
  from .test_downloaders import download_to_temp
label_desc: Use image node_id 1 for calling the TestSRTMSource__combined obj's underlying member method code with example usage: obj.test_trivial(Source) without return types